U.S. patent application number 12/945692 was filed with the patent office on 2011-03-10 for wireless headset system for the automobile.
Invention is credited to Craig Janik.
Application Number | 20110059697 12/945692 |
Document ID | / |
Family ID | 37963868 |
Filed Date | 2011-03-10 |
United States Patent
Application |
20110059697 |
Kind Code |
A1 |
Janik; Craig |
March 10, 2011 |
WIRELESS HEADSET SYSTEM FOR THE AUTOMOBILE
Abstract
A wireless headset system (and method) for connection to a
gateway such as a mobile cellular phone that includes a dock
assembly and a wireless headset. The dock assembly includes a
presence sensor, a first docking connector, and a circuit for
sending a connection signal to the first docking connector in
response to a triggering of the presence sensor. The headset
includes a second docking connector for releasably connecting with
the first docking connector, and connection circuitry for
initiating a wireless connection with the gateway (e.g. mobile
cellular phone) in response to receiving the connection signal via
the first and second docking connectors. The dock assembly further
includes a power connector for receiving electrical power (e.g.
from a car cigarette lighter connector) and for supplying the
electrical power through the first and second docking connectors
and to a battery in the wireless headset.
Inventors: |
Janik; Craig; (Los Altos
Hills, CA) |
Family ID: |
37963868 |
Appl. No.: |
12/945692 |
Filed: |
November 12, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11546038 |
Oct 10, 2006 |
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12945692 |
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60725743 |
Oct 12, 2005 |
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Current U.S.
Class: |
455/41.2 |
Current CPC
Class: |
H04M 2250/02 20130101;
H04M 1/6075 20130101; H04M 1/6066 20130101 |
Class at
Publication: |
455/41.2 |
International
Class: |
H04B 7/00 20060101
H04B007/00 |
Claims
1. A wireless headset system for connection to a gateway,
comprising: a dock assembly that comprises: a presence sensor, a
first docking connector, and a circuit for sending a connection
signal to the first docking connector in response to a triggering
of the presence sensor; a headset that comprises: a second docking
connector for releasably connecting with the first docking
connector, and connection circuitry for initiating a wireless
connection with a gateway in response to receiving the connection
signal via the first and second docking connectors.
2. The system of claim 1, wherein the dock assembly further
comprises: a power connector for receiving electrical power and for
supplying the electrical power to the first docking connector.
3. The system of claim 2, wherein the power connector is a
cigarette lighter connector having: a cylindrical member having a
round sidewall and a first end; a first electrode on the first end;
and at least one second electrode on the round sidewall.
4. The system of claim 2, wherein the presence sensor is a power
noise sensor for detecting electrical noise on the power
connector.
5. The system of claim 1, wherein the presence sensor is a
vibration sensor.
6. The system of claim 1, wherein the presence sensor is a sound
sensor.
7. The system of claim 1, wherein the presence sensor is an
accelerometer.
8. The system of claim 1, wherein the presence sensor is an
infrared detector.
9. The system of claim 2, wherein the headset further comprises: a
battery connected to the second docking connector; wherein the
battery is charged by the electrical power when the first and
second docking connectors are connected together.
10. The system of claim 9, wherein the first docking connector
includes first and second pins for communicating the electrical
power, and wherein the second docking connector includes first and
second pins for receiving the electrical power; the headset further
comprising: a polarity insensitive circuit for receiving the
electrical power from the first and second pins of the second
docking connector, and for supplying the received electrical power
to the battery.
11. The system of claim 1, wherein the dock assembly further
comprises a first magnet and the headset further comprises a second
magnet, and wherein the first and second magnets are disposed to
draw the dock assembly and the headset together such that the first
docking connector connects with the second docking connector.
12. The system of claim 2, wherein: the first docking connector
includes a first pin for communicating the connection signal and
second and third pins for communicating the electrical power; and
the second docking connector includes a first pin for receiving the
connection signal and second and third pins for receiving the
electrical power;
13. The system of claim 12, wherein: the first docking connector
includes a pedestal member that contains the first, the second and
the third pins of the first docking connector; and the second
docking connector includes a cavity for receiving the pedestal
member, the cavity containing the first, the second and the third
pins of the second docking connector.
14. The system of claim 2, wherein the dock assembly further
comprises: a first housing containing the presence sensor, the
circuit, the power connector and a power receptacle connected to
the power connector; and a second housing containing the first
docking connector, wherein the second housing is pivotally
connected to the first housing for selectively covering the power
receptacle.
15. The system of claim 2, wherein the dock assembly further
comprises: a first housing containing the presence sensor, the
circuit, and the power connector; a second housing separate from
the first housing containing the first docking connector; and a
wire connecting the first docking connector of the second housing
to the circuit and the power connector of the first housing.
16. The system of claim 2, wherein the dock assembly further
comprises: a housing containing the presence sensor, the circuit,
and the power connector; a power receptacle disposed separate from
the housing; and a wire connecting the power receptacle to the
power connector.
17. The system of claim 1, wherein the headset further comprises: a
speaker for receiving audio signals and emitting sounds in response
thereto; and a microphone for capturing sound and creating audio
signals in response thereto.
18. The system of claim 1, further comprising: a timing circuit for
ceasing the initiation of the wireless connection in response to
the presence sensor not being triggered for a predetermined amount
of time.
19. The system of claim 1, wherein the dock assembly further
comprises at least one light emitting diode for emitting light in
response to a triggering of the presence sensor.
20. The system of claim 1, wherein the gateway is a mobile cellular
phone.
21. The system of claim 1, wherein the wireless connection is a
Bluetooth wireless connection.
22. A method of connecting a wireless headset to a gateway,
comprising: removably connecting a wireless headset to a dock
assembly via an electrical connection; detecting the presence of a
user using a presence sensor; sending a connection signal from the
dock assembly to the wireless headset via the electrical connection
in response to the detection of the presence of a user; and
initiating a wireless connection between the wireless headset and a
gateway in response to the receipt of the connection signal by the
wireless headset.
23. The method of claim 22, further comprising: supplying power to
the dock assembly, wherein the power is supplied from the dock
assembly to the wireless headset via the electrical connection.
24. The method of claim 23, wherein the detecting of the presence
of a user includes detecting electrical noise in the supplied
power.
25. The method of claim 22, wherein the detecting of the presence
of a user includes detecting vibration.
26. The method of claim 22, wherein the detecting of the presence
of a user includes detecting acceleration.
27. The method of claim 22, wherein the detecting of the presence
of a user includes detecting infrared radiation.
28. The method of claim 22, wherein the detecting of the presence
of a user includes detecting sound.
29. The method of claim 22, wherein the connecting of the wireless
headset to the dock assembly comprises drawing the wireless headset
and the dock assembly together using magnets.
30. The method of claim 22, further comprising: ceasing the
initiation of the wireless connection in response to the presence
sensor not being triggered for a predetermined amount of time.
31. The method of claim 22, further comprising: emitting light in
response to a triggering of the presence sensor.
Description
[0001] This application is a continuation of U.S. application Ser.
No. 11/546,038, filed Oct. 10, 2006, which claims the benefit of
U.S. Provisional Application No. 60/725,743, filed Oct. 12, 2005,
entitled Wireless Headset System for the Automobile, which are
hereby incorporated by reference in entirety.
FIELD OF THE INVENTION
[0002] This invention relates to the field of wireless audio
headsets that are used in conjunction with mobile cellular phones,
and in particular to hands-free communication systems for
automobiles utilizing such headsets.
BACKGROUND OF THE INVENTION
[0003] Bluetooth.RTM. is a short-range, open wireless
communications standard that includes different transmission modes
and can simultaneously accommodate different types of devices.
Bluetooth is often referred to as a PAN (Personal Area Network) and
has the ability to carry real time voice data via a SCO
(Synchronous Connection Oriented) link. An SCO link is a digital
transmission mode where voice packets transmitted back and forth
between an audio gateway (e.g. a mobile cellular phone) and a
headset are sent based on a clock common to both devices. Packets
that are not received by one of either the headset or audio gateway
are not retransmitted. The Bluetooth specification in its entirety
is available for download at www.bluetooth.org. Key specification
documents include the Bluetooth Core Specification v1.2, Hands-free
profile and Headset profile, all of which are incorporated herein
by reference. While the present invention is described with respect
to headsets and systems utilizing the Bluetooth standard, it is not
necessarily limited to this particular communications protocol.
[0004] Wireless audio gateways that utilize Bluetooth are known.
Such gateways are sources of audio, such as a mobile cellular
phone, that route audio transmissions from one communications
system (e.g. a cellular network) to another communications system
(e.g. a Bluetooth wireless transmission system). A wireless
transmission system can include a wireless headset, which is a
wearable audio communication device that includes a wireless
transceiver, a microphone, a speaker (often called a receiver) and
a battery. The headset can both receive an audio transmission and
play the transmission for the wearer, as well as send the wearer's
voice as an audio transmission. A typical headset includes controls
for answering and ending calls, for adjusting the volume of the
audio, and for turning the headset on and off. Recently, more
models of mobile cellular phones are including the gateway
feature.
[0005] Wireless headsets using the Bluetooth communications
protocol allow users to conveniently communicate via their mobile
phone without the constraint of a wire running from the headset to
the phone. Use of a wireless headset eliminates the tangling of
wires that is so common with wired headsets. Wireless headsets
afford new conveniences, such as allowing a user to leave their
phone in their pocket, briefcase, or purse. When the phone rings,
the user can quickly don the headset and answer the call by
activating the answer button on the headset. When used in an office
situation, the user of a wireless headset can roam away from their
desk wearing the headset, and not have to carry their mobile phone
with them. Some users choose to constantly wear the headset, which
further reduces the effort required to answer a call. This function
is particularly useful in the car while driving. In fact, some
jurisdictions have passed laws that prohibit holding a phone while
operating a motor vehicle.
[0006] Wireless automotive hands-free systems (hereafter hands-free
system) are also well known. Such systems are located in
automobiles and include a wireless transceiver, a microphone for
picking up a user's speech, and a speaker system for playing the
caller's audio transmission. Like headsets, the hands-free system
includes controls for answering and ending calls, and for adjusting
the volume of the audio.
[0007] Hands-free systems for use in automobiles have been
developed to enable drivers to make and receive calls with minimal
physical and cognitive interaction. For example, answering a phone
call requires a single button activation. Hands-free systems use
speakers to play the caller's voice. The drawback to hands-free
systems is that there is no privacy during the call. Everyone in
the car listens to the conversation. Additionally, hands-free
systems can produce poor quality transmitted audio because the
microphone is usually located far away from the user's mouth and
the car is a noisy environment. Therefore, hands-free systems,
especially aftermarket integrated systems that plug into cigarette
lighters, can be particularly unpleasant to listen to at the other
end of the conversation.
[0008] One problem with headsets and hands-free systems is that
when the phone moves out of range of the headset or hands-free
system, the connection is lost. One function that is occasionally
implemented in headsets and hands-free systems is to automatically
and periodically page the mobile phone to which it was last
connected in an attempt to reconnect. In theory, the process works
like this: a headset and phone are paired and connected. If the
phone moves out of range of the headset and the connection is lost,
the headset will begin to continually page (attempt to reconnect
to) the phone. When the phone again comes into RF range of the
headset, they automatically reconnect. Ideally, this would take
only a few seconds.
[0009] In the case of when a headset is used in a car, the
reconnect function in practice is not reliable. Many headsets don't
implement the reconnect function because its reconnection
duty-cycle requires power to page the phone, thus reducing the talk
time and standby time (battery life) of the headset. Some headsets
will only attempt to reconnect for a finite length of time and then
stop paging the phone to conserve battery power.
[0010] Another problem with using headsets in a car is that if the
wearer doesn't want to constantly wear the headset, it is easily
lost or misplaced of because there is no fixed storage spot for the
headset. The motions of the car may cause the headset to move
around or fall between the seats. Headsets are small and not easily
located, especially in a dark car.
[0011] Wireless headsets, although convenient, impose the
requirement of having to be charged. A user of a wireless headset
already must remember to charge their mobile phone. There are many
other popular devices that user's must remember to charge, such as
portable MP3 players, Personal Digital Assistants (PDAs), and
gaming devices. A wireless headset is just one more item that must
be carried to the charging location.
[0012] Some manufactures have attempted to make chargers that work
with both mobile phones and headsets. For example, the Motorola
H500 headset includes a USB-type connector that is used for
charging, and thus can be charged using the same car cigarette
lighter charging adapter that is used to charge Motorola mobile
phones that also include the same USB connector. However, when the
headset is being charged, it is inactive (meaning that it is not
connectable to the phone). Furthermore, when the headset is
unplugged, it doesn't automatically connect to the phone. If a call
is received while the headset is charging, the user must unplug the
headset and cycle power to the headset, which would take too long
and the call would be missed. Since charging the headset requires
plugging it into the USB connector at the end of a cable, it is a
two-handed operation that requires a substantial amount of the
user's attention and manual dexterity, and can be difficult for the
driver of a car to accomplish while driving. Lastly, the mobile
phone usually cannot be charged while the headset is charging in
the car, because most cars have only one cigarette lighter.
[0013] FIG. 1 shows the Jabra model BT250 headset manufactured by
GN Netcom of Denmark, in a charging dock. This dock can be used in
the car in conjunction with an automotive DC-to-DC cigarette
lighter adapter. However, it also takes two hands to place the
Jabra BT250 into the dock, or remove the Jabra from the dock, due
to the tight friction fit between the headset and the dock.
Furthermore, the headset is not in a functional state while
charging. If the user's phone rings, it is unlikely that the
headset can be removed from the dock, powered up and connected to
the mobile phone in time to answer the call.
[0014] What is needed is a wireless headset system for an
automobile that provides an effective docking solution for a
wireless headset that allows operation during charging and easy
removal for answering calls. The system should also incorporate an
improved automatic reconnection function such that the headset
battery is not needlessly drained, yet is transparent to the user
during use. Lastly, the system should allow for simultaneous
charging of the phone and headset.
SUMMARY OF THE INVENTION
[0015] The present invention solves the aforementioned problems by
providing a wireless car headset system that automatically
initiates a reconnection between a gateway and the headset when the
presence of the user is detected while the headset is docked with a
docking assembly.
[0016] A wireless headset system for connection to a gateway
includes a dock assembly and a headset. The dock assembly includes
a presence sensor, a first docking connector, and a circuit for
sending a connection signal to the first docking connector in
response to a triggering of the presence sensor. The headset
includes a second docking connector for releasably connecting with
the first docking connector, and connection circuitry for
initiating a wireless connection with a gateway in response to
receiving the connection signal via the first and second docking
connectors.
[0017] A method of connecting a wireless headset to a gateway
includes removably connecting a wireless headset to a dock assembly
via an electrical connection, detecting the presence of a user
using a presence sensor, sending a connection signal from the dock
assembly to the wireless headset via the electrical connection in
response to the detection of the presence of a user, and initiating
a wireless connection between the wireless headset and a gateway in
response to the receipt of the connection signal by the wireless
headset.
[0018] Other objects and features of the present invention will
become apparent by a review of the specification, claims and
appended figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a side view illustrating a Jabra wireless headset
in a charging dock.
[0020] FIG. 2 is a partially exploded perspective view of the
wireless headset and car charging dock of the wireless headset
system for the automobile.
[0021] FIG. 3 is bottom view of the wireless headset.
[0022] FIG. 4 is a side view of the wireless headset as worn by a
user.
[0023] FIG. 5 is a top view of the wireless headset illustrating
the charging port thereof
[0024] FIG. 6 is an exploded perspective view of the wireless
headset.
[0025] FIG. 7 is a perspective view of the internal components of
the wireless headset.
[0026] FIG. 8 is a perspective view of the car charging dock.
[0027] FIG. 9 is a perspective view of the car charging dock with
the dock module rotated to its open position.
[0028] FIG. 10 is an exploded view of the car charging dock.
[0029] FIG. 11 is an exploded view of the dock module of the
charging dock.
[0030] FIG. 12 is a top view of a main PCB of the charging
dock.
[0031] FIG. 13 is a bottom view of the main PCB of the charging
dock.
[0032] FIG. 14 is a schematic diagram of the car charging dock and
wireless headset of the wireless headset system.
[0033] FIG. 15 is a side view of the wireless headset connected to
the car charging dock.
[0034] FIG. 16 is a partial side cross sectional view of the
wireless headset connected to the dock module.
[0035] FIG. 17 is a flow chart describing part of the reconnect and
LED lighting functions of the charging dock.
[0036] FIG. 18 is a perspective view of a desk charging dock.
[0037] FIG. 19 is a perspective view illustrating a dock module
that can be mounted remotely.
[0038] FIG. 20 is a perspective view illustrating a dock module
that is mounted remotely.
[0039] FIG. 21 is a partially exploded view illustrating a car
charging dock with a tethered auxiliary 12-volt power port.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The present invention is a wireless headset system that
incorporates a convenient docking solution and triggers the
reconnection function based upon sensing the presence of the user.
Referring now to FIG. 2, a wireless headset system 202 for the
automobile is comprised of a car charging dock 204 and a wireless
headset 206. The wireless headset 206 attaches with minimum effort
to the car charging dock 204 via a magnetic coupling. An LED
lightpipe ring 68 on the charging dock 204 lights in response to
detected presence of a user. When docked on car charging dock 204,
wireless headset 206 is triggered to reconnect with the user's
mobile phone when the presence of the user (e.g. through vibration
sensing) is detected. The reconnection function is terminated, and
the LEDs 76a-76h of lightpipe ring 68 are switched off after an
interval of time without vibration. The reconnection function can
be switched off via a switch on car charging dock 204. Car charging
dock 204 also includes an auxiliary cigarette lighter 12-volt port
so that a mobile phone can be charged while wireless headset 206 is
docked and charging. The components of wireless headset system 202
for the automobile will be described below in more detail, followed
by a description of its operation. It should be noted that while
the present invention is described with respect to a particular
configuration and Bluetooth wireless protocol, certain other
configurations and protocols can be used and still be within the
scope of the present invention.
Headset
[0041] Wireless headset 206, shown in FIGS. 3 and 4, is preferably
a Bluetooth v1.2 compliant wireless headset. FIG. 3 shows that
headset 206 includes a cover 2, an ear hook assembly 208 for
attaching headset 206 to the wearer's ear, an answer button 4 for
answering calls, a lightpipe 6 that ports light from a status LED,
a volume control button 5, and a foam cover 8 made of open-cell
foam that is positioned against the wearer's ear when headset 206
is donned. FIG. 4 shows the angle of the wearing position and how
ear hook assembly 208 secures headset 206 to the wearer's ear.
Headset 206 also includes an sliding on-off button (not shown).
[0042] FIG. 5 shows the side of headset 206 that faces the wearer's
ear when in use. A headset charging spring contact (right) 11, a
re-connect signal spring contact 12, and charging spring contact
(left) 13, are nested inside a charging port 10. FIG. 6 is an
exploded assembly view of headset 206 with some components removed
for the purpose of clarity. Charging port 10 snaps to an inner
cover 18. Referring to FIG. 6 and FIG. 14, a headset PCB 16
includes the various electronic components required to implement
communications over a known protocol (such as Bluetooth) and
includes a Bluetooth single-chip microprocessor 100 with integral
memory, a battery charging integrated circuit 98, and charging
polarity-swapping circuit 96, status LED, an antenna chip, and a
plurality of switches. A receiver 20 is located in a cutout in
headset PCB 16. Microprocessor 100 can be (but need not be) a
BC358239A single chip Bluetooth v1.2 system, manufactured by
Cambridge Silicon Radio of Cambridge, England. Charging spring
contact (right) 11, re-connect signal spring contact 12, and
charging spring contact (left 13) are soldered to solder pads on
headset PCB 16. Headset 206 also includes a rechargeable battery 14
(e.g. lithium-ion polymer). Cover 2, inner cover 18, charge port
10, and ear hook assembly 208 are manufactured of injection-molded
plastic. Cover 2 and inner cover 18 together provide a protective
enclosure for wireless headset 206. FIG. 7 shows that a
nickel-plated carbon steel receiver plate 22 can be attached to the
inside surface of inner cover 18. A mic-side magnet 24 made out of
neodymium is attached to inner cover 18. A receiver-side magnet 26
made out of neodymium is attached to inner cover 18 in a circular
slot in receiver plate 22 so that receiver-side magnet 26 is flush
with receiver plate 22.
[0043] Headset 206 firmware includes functional implementations of
the Bluetooth Headset Profile and Hands-free Profile. Headset 206
firmware also includes an implementation of the automatic reconnect
function, which attempts to page the phone to which headset 206 was
last connected unless headset 206 is currently connected to a
phone. The operation of reconnect function is covered below.
Car Charging Dock
[0044] FIG. 8 and FIG. 9 show that car charging dock 204 includes a
form that allows it to be inserted into and connect electrically to
a standard car cigarette lighter receptacle. Car charging dock 204
includes an external 12-volt contact 46 and external ground
contacts 48a and 48b, which make contact with corresponding 12-volt
and ground contacts inside the cigarette lighter receptacle. FIG. 9
shows that dock module 210 can pivot up approximately 80 degrees to
allow access to an auxiliary 12-volt cigarette lighter receptacle
(to plug in other devices such as a charger for a cell phone).
Right lock bar 32 and left lock bar 34 are spring-loaded inside car
charging dock 204 so that they protrude into corresponding right
lock bar cavity 56 and left lock bar cavity 58 in dock module 210,
thereby locking dock module 210 in the closed position, as shown in
FIG. 8.
[0045] The exploded view of charging dock 204 in FIG. 10 shows a
left dock enclosure 30 and a right dock enclosure 28 that are
fastened together to pivotably constrain dock module 210. Right
lock bar 32, left lock bar 34, and lock button 36 are fit together
and slide within car charging dock enclosure such that portions of
right lock bar 32 and left lock bar 34 protrude from holes in right
enclosure 28 and left enclosure 30, respectively. The left lock bar
34--right lock bar 32--lock button 36 sub-assembly is forced toward
dock module 210 by a lock spring 38. A dock main printed circuit
board (PCB) 212 is also a component in car charging dock 204.
External 12-volt contact 46 and internal 12-volt contact 42 share a
common circuit which is connected to a 12-volt input on dock main
PCB 212. External ground contacts 48a and 48b and internal ground
contact 44 also share a common circuit and are connected to the
ground input on dock main PCB 212. External 12-volt contact 46 is
constrained by features in dock enclosure (right) 28 and dock
enclosure (left) 30. An external 12-volt spring 52 located inside
external 12-volt contact 46 ensures a compliant contact between
external 12-volt contact 46 and the 12-volt contact inside a
conventional car cigarette lighter receptacle.
[0046] FIG. 12, an isometric view of the top side of dock main PCB
212, shows a flexible circuit connector 102, a vibration sensor
switch 86, and a plurality of components associated with a DC-DC
power conversion circuit, all functionally connected by main PCB
212. Vibration sensing is used to detect the presence of a user
either by detecting movement of the user in the car and/or the
operation of the car by the user. An exemplary vibration sensor
switch is part number VBS03-02, provided by Oncque Corporation, of
Taiwan, which is ideal for sensing vibrations.
[0047] FIG. 13, an isometric view of the bottom side of dock main
PCB 212, shows a microcontroller 88, an automatic reconnect on-off
switch 108, an LED driver integrated circuit (IC) 106, and a
plurality of components associated with a DC-DC power conversion
circuit, all functionally connected by dock main PCB 212. An
exemplary microcontroller 88 is an 8-bit microcontroller, part
number PIC12F509-I/SN, manufactured by Microchip of Chandler, Ariz.
A variety of other support components are required but now shown.
The parasitic power usage of dock main PCB 212 when headset 206 is
not charging or is fully charged, and when microcontroller 88 is in
a low power (sleep) mode and monitoring vibration switch 86, is
very low (i.e. less than 1 milli-amp).
Dock Module
[0048] Now referring to FIG. 11, dock module 210 comprises a dock
module cover 60, a lightpipe ring 68, neodymium magnets 70a 70b, a
dock charging pads PCB 72, a dock module PCB 74, LEDs 76a-76h, a
dock spring-pin connector 78, a dock module rear cover 62, and a
pivot plate 64 covered by a pivot plate cover 66. A flex circuit 40
electrically connects dock module 60 to dock main PCB 212. Dock
module PCB 74 is electrically connected to dock charging pads PCB
72 by three wires as schematically shown in FIG. 14. Flex circuit
40 is also shown with one end located against pivot plate 64 and
retained by pivot plate cover 66. Flex circuit 40 is routed through
a hole in pivot plate 64 and extends inside car charging dock 204
and is mechanically and electrically connected to dock main PCB
212, as shown in FIG. 10. When dock module 210 is assembled,
electrical contact pads on flex circuit 40 make contact with
spring-pins on dock module spring connector 78, which are soldered
onto dock module PCB 74, and which in turn includes an electrical
circuit that routes a 7-volt circuit 82, a ground circuit 84, and a
reconnect signal circuit 80 to dock charging pads PCB 72.
Headset Magnetic Attraction and Orientation
[0049] Headset 206 may be connected to car charging dock in one of
two orientations where headset is rotated 180 degrees with respect
to an axis normal to the cylindrical cross-section of car charging
dock 204. These two orientations are shown in FIG. 2 and FIG. 15
respectively. The location of mic side magnet 24 and receiver side
magnet 26 are shown in FIG. 7. The two orientations are partly
controlled by the shape of the cavity in charging port 10 as it
fits onto the corresponding shape of charging pedestal 54 on dock
module 210, as well as the polarity of magnets 70a and 70b in dock
module 210 and magnets 24 and 26 in headset 206. Mic side magnet 24
and receiver side magnet 26 are assembled in inner cover 18 so the
south pole of each magnet faces toward the side of headset 206 that
faces car charging dock 204 when docked. Magnets 70a and 70b are
installed in dock module cover 60 so that the north pole of each
magnet faces headset 206 when headset 206 is docked. Therefore,
headset 206 is always pulled toward car charging dock 204 in either
orientation.
[0050] Receiver side magnet 26, receiver plate 22, and either
magnet 70a or 70b (depending on headset orientation) constitutes
one magnetic coupling group when headset 206 is docked. Mic side
magnet 24 and either magnet 70a or 70b constitutes a second
magnetic coupling group when headset 206 is docked. Receiver side
magnet 26, receiver plate 22, and mic side magnet 24 are sized so
that in combination with the receiver metal and magnet, the
magnetic force is even between the two magnetic coupling groups
when headset 206 is magnetically docked to dock module 210.
Block Diagram of System
[0051] FIG. 14 is a schematic diagram of wireless headset system
202 when headset 206 is attached to car charging dock 204. There
are two main subsystems in car charging dock 204, a DC-DC power
conversion subsystem and a vibration sensing and reconnection
subsystem. The DC-DC power conversion subsystem includes a
plurality of components associated with a DC-DC power conversion
function that converts 12-volt DC power to 7-volt DC power for
charging headset 206 and powering LEDs 76a-76h. External 12-volt
contact 46 and external ground contacts 48a and 48b provide 12-volt
power to dock main PCB 212 when car charging dock 204 is inserted
in a car cigarette lighter. External 12-volt contact 46 is
connected by a wire circuit to internal 12-volt contact 42 and
external ground contacts 48a and/or 48b are connected by a wire
circuit to internal ground contact 44.
DC Charging Circuit
[0052] Referring to FIG. 14 and FIG. 16, DC-DC power conversion
sub-assembly includes two circuits: 7-volt charging circuit 82 and
ground circuit 84. These circuits run from dock main PCB 212,
through flexible circuit 40, through dock module spring connector
78 to dock module PCB 74, and terminate at the two outer gold
plated pads of dock charging pads PCB 72. Headset 206 may be docked
in one of two positions which are rotated 180 degrees from each
other. Therefore, depending on the orientation of headset 206,
charging contact spring (right) 11 makes contact with one of either
7-volt charging circuit 82 or ground circuit 84, via a gold-plated
contact on dock charging pads PCB 72. Likewise charging contact
spring (left) 13 makes contact with the other of the charging
circuit 82 or ground circuit 84. Charging polarity-swapping circuit
96 is a full bridge rectifier circuit that provides the correct
polarity voltage to battery charging circuit 98 regardless of the
orientation of headset 206 on dock module 210. Such a circuit
(which provides the desired output polarity to the battery no
matter which incoming polarity orientation is provided) can be
generically referred to as a polarity insensitive circuit.
Led Power Circuit
[0053] DC-DC power conversion sub-assembly also includes an LED
power circuit 94 that is generated by LED driver 106 and runs from
dock main PCB 212 through flexible circuit 40, through dock module
spring connector 78 to dock module PCB 74, and then to each of LEDs
76a-76h. Microcontroller 88 includes a control input into LED
driver 106 so firmware programming in microcontroller 88 controls
the power sent to LEDs 76a-76h.
Re-Connect Circuit
[0054] Microcontroller 88 includes an output port that drives a
reconnect signal circuit 80. This output port runs from
microcontroller 88, through flexible circuit 40, through dock
module spring connector 78, through dock module PCB 74 to the
center gold-plated contact on dock charging pads PCB 72. When
headset 206 is docked on car charging dock 204, reconnect signal
spring pin contact 12 on headset 206 makes electrical contact with
the center gold-plated contact on dock charging pads PCB 72, so
reconnect signal circuit 80 is connected to a reconnect signal port
110 on microprocessor 100. Firmware resident on microprocessor 100
monitors the logic level on reconnect signal port 110. If the logic
level on reconnect signal circuit 80 and thus at reconnect signal
port is low, the reconnect function in firmware is disabled. If the
logic level on reconnect signal circuit 80 and thus at reconnect
signal port 110 is high, the reconnect function in firmware is
enabled.
[0055] The reconnect function may be turned off by sliding button
50 of reconnection on-off switch 92 to the off position. Switch 92
controls a logic level voltage on a port on microcontroller 88.
Firmware in microcontroller 88 controls the logic level on
reconnect signal circuit 80 depending on the state of logic level
at a port on microcontroller 88.
Vibration Sensing Circuit
[0056] Vibration sensor 86 is functionally connected to a port on
microcontroller 88 so that in the presence of no vibration a logic
low level is present at microcontroller 88 port, and in the
presence of vibration a high logic level is present at
microcontroller 88 port.
System Operation
[0057] The operation of wireless headset system 202 will now be
described, and in particular with respect to operation in
conjunction with a user's mobile phone in a hands-free mode.
Docking
[0058] When the user is not actively on a mobile phone call,
headset 206 may be removed from the user's ear and placed on car
charging dock 204. The act of placing headset 206 on car charging
dock 204 involves minimal effort by the user because the magnetic
attachment means acts to pull headset 206 into the correct position
and orientation when headset 206 comes in close proximity to dock
module 210. The protrusion of charging pedestal 54 into charging
port 10 on headset 206 stabilizes headset 206 on dock module 210.
If headset 206 is placed in close proximity to dock module 210 but
mic side magnet 24 and receiver side magnet 26 are not exactly
lined up with magnet 70a and 70b respectively, the magnetic
attraction imparts a rotational force to headset 206 as well as a
linear attractive force, aiding to align headset 206 as it placed
near dock 204. The spring forces of charging spring contact (right)
11, connect signal spring contact 12, and charging spring contact
(left) 13 are such that the magnetic force between the two coupling
groups overcomes the combined spring force. Headset 206 is thus
securely attached to car charging dock 204 and is not jarred loose
by vibrations or shocks typically experienced in cars.
Headset Charging
[0059] If car charging dock 204 is powered by cigarette lighter
receptacle (where the receptacle is either always powered or only
powered when the car's ignition is turned on), and headset 206 is
docked on dock module 210, the headset battery charging circuit 98
will charge rechargeable battery 14 until rechargeable battery 14
is fully charged. Rechargeable battery 14 charges in either of two
attached orientations, and battery charging circuit 98 charges
rechargeable battery 14 regardless of whether headset 206 is turned
on or off.
Headset Connection While Docked
[0060] In the description below it is assumed that headset 206 and
a mobile phone have been previously paired and are thus
discoverable and connectable with respect to one another using a
communications protocol such as Bluetooth. Bluetooth devices that
have been paired discover other Bluetooth devices by periodically
entering a paging mode (headset), and a page scan mode (phone). The
Bluetooth specification describes the process for device discovery,
paging and page scan substates, and the establishment of
asynchronous connectionless (ACL) links, and synchronous
connection-oriented (SCO) links. The process of entering page scan
and paging substates, and the subsequent link management and other
processes leading up to being connected, is referred to as
connecting or reconnecting. When a mobile phone and wireless
headset 206 have established a connection via this process and are
ready to initiate an SCO link for audio transmission, and an ACL
link for sending AT commands (but no phone call is taking place),
they are referred to as being connected. When a call is in progress
where audio is being transferred via the SCO connection, the
headset 206 and the mobile phone are said to be in an active
state.
[0061] Firmware running on microprocessor 100 in headset 206
includes a conditional reconnection function, whereby headset 206
attempts to reconnect with the mobile phone to which it was last
connected, if headset 206 is not already connected to a mobile
phone. This reconnection attempt consists of headset 206
broadcasting page messages. The reconnect function monitors the
port on microprocessor 100 to which reconnect signal circuit 80 is
connected. The reconnect function operates conditionally such that
when reconnect signal circuit 80 is a logic low level, the
reconnect function is not executed. When headset 206 is not docked,
or when car charging dock 204 is not powered, reconnect signal
circuit on headset 206 is pulled to a logic low level. When the
dock microcontroller 88 drives reconnection signal circuit 80 to a
logical high level and then a logical low level, and headset 206 is
docked on dock module 210, a logic high level is present at a port
on microprocessor 100 in headset 206, and the reconnect function is
executed. The falling logic level (i.e. logic level transition)
triggers the reconnection function. When triggered, the
reconnection attempt lasts approximately 10 seconds. Therefore,
ideally, microcontroller 80 toggles reconnection signal circuit 80
between a logic low level and a logic high level about once every
30 seconds.
[0062] FIG. 17 is a flowchart that shows the function of car
charging dock 204 with respect to lighting LEDs 76a-76h and for
triggering the reconnect function. When headset 206 is not docked
on car charging dock 204, reconnect signal circuit 80 is pulled low
at a port on microprocessor 100 on headset 206, so headset 206 does
not initiate a reconnection attempt. When headset 206 is docked on
car charging dock 204 that is located in a cigarette lighter that
is not receiving power (i.e. the key has not activated the ignition
switch) the logic level on reconnect signal port 110 is low so
headset 206 does not attempt to reconnect. If headset 206 is docked
on car charging dock 204 that is receiving power (i.e. either the
key has activated the ignition or the cigarette lighter receptacle
always receives power) and the vibration switch 86 senses
vibration, microcontroller 88 toggles the reconnect signal port 110
between high and low in a duty cycle causing headset 206 to attempt
a reconnect to the phone to which headset 206 was last connected
(unless it is already connected to an audio gateway such as a
mobile phone wherein the headset ignores the toggling signal),
during which LEDs 76a-76h are turned on, as indicated in FIG. 17.
If the reconnection fails, another reconnection attempt will be
made upon the next transition of the reconnect signal port 110. If
the reconnection is successful, the reconnection function ignores
subsequent logic level transitions of the reconnect signal port
110.
[0063] Firmware in microcontroller 88 includes an elapsed time
counter monitoring function. The elapsed time counter starts when
power is applied to car charging dock 204 or restarts the count
after every instance that a vibration is sensed by vibration sensor
86 and by microcontroller 88. When the elapsed time monitor
function reaches the timeout counter limit without detecting any
vibration (e.g. 10 minutes), firmware executing in microcontroller
88 holds reconnect signal circuit 80 low which causes the reconnect
function in headset 206 to cease (and LEDs 76a-76h are turned off).
Referring to FIG. 17, microcontroller 88 regards its initial power
up as a sign of user presence, and starts the reconnection duty
cycle and applies power to the LEDs regardless of the state of the
vibration sensor.
[0064] The result is that as long as a user is present with the key
in the ignition, or the vehicle is occasionally moving, or the user
makes vibrations inside the car (the user is present), headset 206
will continually attempt to reconnect to the mobile phone to which
it was last connected, unless it is already connected to a mobile
phone. If car charging dock 204 is placed in an ignition that is
always powered (not dependent on a key in the ignition), and the
user leaves the car parked, for example at a long term parking lot,
then after 10 minutes of no vibration (the user is not present),
headset 206 will not attempt to reconnect with the phone, thus the
parasitic power draw of the wireless headset system 202 is
reduced.
[0065] Thus wireless headset system 202 provides the benefit of
headset 206 attempting to automatically reconnect with the user's
mobile phone when headset 206 is docked on car charging dock 204,
and thus connected to a large power source (the car's battery), but
only when vibration (i.e. presence) is detected and only if the
headset is not already connected to the mobile phone. When headset
206 is not docked and without access to the car's battery, the
reconnection function is not automatically executed, thus
preserving the battery life of headset 206. If the headset 206 is
not docked, it is still possible to manually initiate a
reconnection by activating the answer button on the headset. As
stated above, operating button 50 (which toggles reconnection
on-off switch 92, allows the user to enable or disable automatic
reconnection. FIG. 17 shows that the vibration detection scheme is
also used to turn LEDs 76a-76h on and off. The activation of LEDs
76a-76h based on vibration sensing is preferably not de-activated
when automatic reconnection on-off switch 92 is switched to disable
reconnection.
Desk Dock
[0066] FIG. 18 illustrates the implementation of the reconnection
signal circuit in a desktop charging dock 214 that can be used in
the home or office. In this embodiment, no vibration sensing is
necessary because the dock is powered by AC line power. Desktop
charging dock 214 includes a charging pedestal 118 that is the same
shape as charging pedestal 54 on dock module 210, and a
reconnection on-off switch 112 that disables or enables the
reconnect function. When the reconnection function is enabled, a
microcontroller internal to desktop charging dock 214 continually
toggles reconnection signal circuit so that when headset 206 is
placed on desktop charging dock 214, headset 206 perpetually
attempts to connect to the last audio gateway (mobile phone) to
which it was connected (assuming it is not already connected to an
audio gateway). For this configuration, it may be desired to omit
the LEDs that indicate reconnection is under way.
[0067] When the user moves out of the RF range of headset 206 while
the headset is docked on desktop charging dock 214, the connection
between headset 206 and mobile phone is lost. When user moves
within RF range of headset 206 docked on desktop charging dock 214,
headset 206 automatically reconnects with the user's mobile
phone.
Alternate User Presence Detection Schemes
[0068] There are other techniques (other than sensing vibration)
for detecting user presence that can be used to trigger
reconnection. For example, instead of sensing vibration, presence
can be detected by using a solid-state accelerometer connected to
an analog-to-digital port on microcontroller (e.g. an ADXL203 Dual
Axis Accelerometer, provided by Analog Devices, Inc. of Norwood,
Mass.), which would sense movement and/or acceleration of the car
(and possibly certain vibrations as well).
[0069] Another technique for detecting user presence can be a
circuit for monitoring alternator noise present on the cigarette
lighter power circuit. When the car engine is running there is a
60-cycle ripple present in the power system, due to the effect of
the alternator. A noise sensing circuit including a filter and a
trigger can detect this ripple and would be connected to an input
port on a microcontroller (where firmware on the microcontroller
continually monitors the port).
[0070] Yet another technique for user presence detection involves
the use of a circuit connected to a microphone for sensing sound.
The microphone component and an audio filter is connected to a
trigger, which in turn is connected to a port on the
microcontroller. The audio filter insures that only sound in a
certain frequency band will activate the trigger so as to avoid
needless false positive detections. Firmware in the microcontroller
would always monitor the port, even during sleep mode.
[0071] Yet one more user presence technique could be a circuit that
includes a low power IR detector. An IR detector connected to a
filter and a trigger could be connected to a port on
microcontroller. Firmware in the microcontroller always monitors
the port, even during sleep mode. When a user is present, IR energy
is detected, and the logic level at the trigger circuit is
switched.
[0072] Thus, for any of these alternate user presence detection
techniques, the vibration switch 86 can be replaced by the
accelerometer, the power noise sensing circuit, the sound sensing
microphone and related circuit, or the IR detector and related
circuit described above, and/or combinations thereof.
Dash Mounting and Connection
[0073] FIG. 19 and FIG. 20 show how dock module 210 can be separate
from car charging dock 204, for separate location such as on a car
dash. A dock module tether assembly 218 includes all the components
in dock module 210 except a dock tether adapter 124 is used in
place of dock module cover 60. FIG. 20 shows that dock module 210
includes a dash mount dock module adapter 126 in place of pivot
plate. Dock module 210 is removed from car charging dock 204 by
removing a screw that passes through access hole 132 and screws
into screw boss 130 in dock module rear 62. Dash mount dock module
adapter 126 attaches to dock module 210 by fitting the undercut on
dash mount dock module adapter 126 into the opening in dock module
rear 62 and fastening the screw in screw boss 130. Dock module
tether assembly 218 includes a dash mount tether 128 that is a
covered wire circuit bundle that brings all of the same charging,
LED power, and reconnection circuit lines to dock module 210. In
one embodiment dock module 210 is mounted with the use of
double-sided foam tape that is placed on the rear side of dash
mount adapter 126. In another embodiment dock module 210 is
removably mounted to the dash with double-sided Velcro tape.
[0074] Referring now to FIG. 19, car charging dock 204 can be
placed into an auxiliary 12-volt cigarette lighter power receptacle
216, which is then wired to the car's 12-volt and ground circuit.
Thus, car charging dock 204 connected to power receptacle 216 can
be fastened underneath the dash out of sight of the user. Wireless
headset 206 is docked to dock module 210 in the same way as
described above. All of the charging and reconnection functions are
the same as well.
[0075] In yet one more alternate embodiment shown in FIG. 21, a car
charging dock 220 includes a remotely tethered auxiliary power
receptacle 222. Charging circuit in dock 220 includes +12 volt
power and ground pass-through circuits that are connected to power
cable 134, which is connected to an auxiliary cigarette lighter
power receptacle 222 , allowing other cigarette lighter charging
devices, for example the user's mobile phone, to be powered while
car charging dock 220 is place in the car's cigarette lighter.
[0076] It is to be understood that the present invention is not
limited to the embodiment(s) described above and illustrated
herein, but encompasses any and all variations falling within the
scope of the appended claims. For example, while the present
invention is described primarily in conjunction with a mobile
cellular telephone serving as an audio gateway, any gateway (audio,
video, data, etc.) can be used as part of the present invention.
Examples of such gateways can include a mobile cellular telephone,
a personal computer, an internet phone (voice over IP), etc.
* * * * *
References